Fun future AR-15 project

So I just bought two "assault rifles" to circumvent my current state of residence's OCT 1 ban on them. I get to shoot a normal M4 at work, so I want to do something interesting with these. I plan on eventually building one lower specifically to be lefty friendly, up to and including a full left handed upper (eg a stag arms model 8hl). The second I am probably going to turn into a more basic AR15 build for my wife, once she realizes that shooting AR15 platform rifles = super fun. I think I know what parts (and part kits) I am going to use, but I don't plan on doing it anytime soon. Prices are too high right now.

Ideally, I am going to use the Stag Arms lower to build out a lefty AR in 5.56 (as best I can, since I wasn't able to purchase a full lefty AR lower), and may eventually supplement that with a separate lefty upper. Probably a similar build out, but in .300 blackout. Possibly a shorty barrel/suppressor setup, assuming I can do it successfully with a piston setup and without altering the lower much. Hopefully I don't have to swap out the buffer. So anyway, since traffic in the armory has been low until recently, here is a chance for the peanut gallery to chime in.

1.) What lower parts kit should I buy? I like the spikes tactical enhanced LPK, but am not sold on the pistol grip they offer. Should I go with a more basic one and then pick out a better trigger and grip individually?

2.) What type of rail system should I use? I don't have anything in mind here, but I will probably go with a quad rail/free float setup, since that is what I'm used to shooting.

3.) I'm undecided on optics.

4.) Iron sights. I want some kind of flip up iron sights, but am seriously undecided on that as well. Either way, I want them to integrate with the optics, either so I can flip the sights in or out as needed, or use either one as I so choose.

5.) I'm going to install an adjustable stock, but am unsure as to what I want there.

Don't be surprised/annoyed when I completely ignore your suggestions and do what I want to my rifle, but look at this as an opportunity to show me what you would do if you had time and money to spare.

Attached Thumbnails

"No. Listen to me because I know what I'm talking about here." -- Hannibal

1.) What lower parts kit should I buy? I like the spikes tactical enhanced LPK, but am not sold on the pistol grip they offer. Should I go with a more basic one and then pick out a better trigger and grip individually?

2.) What type of rail system should I use? I don't have anything in mind here, but I will probably go with a quad rail/free float setup, since that is what I'm used to shooting.

3.) I'm undecided on optics.

4.) Iron sights. I want some kind of flip up iron sights, but am seriously undecided on that as well. Either way, I want them to integrate with the optics, either so I can flip the sights in or out as needed, or use either one as I so choose.

5.) I'm going to install an adjustable stock, but am unsure as to what I want there.

Here comes your neighborhood AR-15 parts dealer.
1. To save money, its best to just get an entire kit. If you want a good trigger feel, the second cheapest way to do it is to get a high-tolerance lower receiver and get a good brand single stage military trigger. Not all lower receivers are created the same and tolerances matter, even if its within mil-spec, when it comes to trigger feel. My favorite bang-for-buck combo is a FAMCO lower receiver (billet or forged) and a CMMG lower parts kit.

Forged lowers are harder to find. I love Forged, as opposed to billet, because you can make them smaller and lighter than billets because the forging process makes them stronger, even with the cheaper milspec aluminum (vs 7075 aluminum in some billets). By the way, my company carries the SWAT billet lower pictured in the left, but it has a US flag (facing forward) on the right side with my company logos printed under it. We also carry the FAMCO lowers, 'blemished' because I dropped a box and they have very minor scratches in the anodizing. If you want to buy one from me, let me know so I can give you a bullshido discount. (I can also sell you a lower parts kit.) We won't be the cheapest combo out there but

2. Its a PITA to install a free float rail kit if you never took apart a gas block/front sight base before. I think they are a bit overrated, especially for a combat AR. If you want to do the work, free float rails tend to be cheaper. If you don't want to do the work, I recommend a troy battlerail. It isn't a free float rail but it is supposed to be solid enough to mount optics. Another option is to get a Daniel Defense omega rail. Kinda pricy but its the only free float rail on the market that does not require disassembly of the gas block/front sight. If you like brand-name bling you can also go on ebay and get one of the mil-issue surplus knight's RIS kit. Good way to get covers, rail and foregrip in one package

3. Aimpoint Pro is a good all-around optic, awesome battery life, and can be had for under 400 bucks. Another option is an Eotech, but they are backordered like crazy right now. My company runs a CompM4 with a QD mount, totally don't need an 800 dollar optic, but we do for the bling factor. My recommendation is start with irons, move into Aimpoint Pro, then after you shoot for a while, decide on something more expensive like Trijicons, Aimpoint micros, etc. Please read up on co-witnessing if you don't know already.

4. Its worth it to go to a more expensive (100 dollars ish) flip up sight, especially for the rears. MBUS is okay but it is kind of hard to shoot very good groups with it. It isn't as precisely made nor will your sight picture all that clear. I can do a 3-4" group with my old, 600 dollar, cheapo DSA AR-15 with this sight, but I think if I got a good rear sight I could do 1-2" groups.

5. Adjustable stocks: Honestly, I am happy with TAPCO cheap civilian spec tube stocks. You can get commerical spec buffer tubes or milspec ones. Milspec ones tend to be a bit 'nicer' and are very tight. My personal preference is a commercial spec tube. The milspec ones don't really offer anything better than commercial tubes, except for a tight fitment. I actually dislike super tight stocks; when you shoulder your rifle the commercial tube stock isn't going to move around and affect your anyways, and I don't like the extra effort I have to use to retract a milspec stock.

If you want something a bit nicer, go for a magpul CTR stock.

I generally don't like blinging out my guns too much, so I have no useful input on the more fancy stocks offered by magpul.

I did carry a nice, very price competitive, US made stock kits from Phoenix Technologies. I ran out of stock on that one. I may order more; when I do, I'll have full stock kits to offer you (stock, buffer tube, endplate, castle nut, buffer and spring) for a very good price. Description is on my website even if its on backorder.

Really, possibilities are limitless. I really like 'mils-spec' looking ARs. That is, standard front sight base, standard non-float rails, forged receivers and single stage triggers. It does everything that I could possibly use it for in a real life scenario.

I forgot to carry bolt carrier groups.
As long as the gas rings are to spec (it should be able to support its own weight, or even better, support the weight of the entire BCG when it is standing on the bolt face.. but when brand-new, you should be able to pull the bolt back out and push back in without having to use excessive force)

On some theoretical level, its good to get a completed upper which would include a BCG. This is because, once again theoretically, the headspacing would be done at the factory. The reality is, CNC machines are so good now that you will very rarely have headspacing issues with any upper(barrel extension)/BCG combo. In fact, I don't think manufacturers 'mate' uppers with BCGs. If anything, probably a quick check with a go/nogo gauge.

Unless you wish to someday go through the trouble of owning a full auto rifle, don't worry about 'full auto rated' or 'full auto' 'M16 spec' bolt carrier groups.

There are a bunch of materials that BCGs are cut from. Once again, I wouldn't worry too much about it. Milspec is to use carpenter 158 steel for the bolt and 8620 for the bolt carrier group. This is a bit more than good enough. Better than milspec materials are typically ones that use a 9310 steel for the bolt.

What is more important is surface lining. Milspec is chrome-lined. Its pretty neat, so if you want, spend the money on that. If not, chrome lined interior or nitraded BCG is also good enough. I don't recommend spending money on a nickel boron trated BCG.. it is way overpriced (it costs the manufacturer very little to apply it..).

Because it is a critical part, make sure they are high pressure tested and magnetic particle inspected. It'll be advertised as so. Even if they just do HPT/MPI batch testing..

I have a few BCGs that are your standard HPT/MPI, C158 steel BCGs. Semi-auto. I like them and run it in a few of our company guns. (and hense why I carry them) once again, if you want to get them from me, please shoot me a pm/email. my email is on my website in my sig.

Thanks!
I made an error in the first post. A lot of 'milspec' forged lower receivers are 7075 aluminum, including the FAMCO lowers I mentioned (they are a OEM supplier to many of the 'big brand' lower receivers)

A minor correction, my muzzle devices don't work so well as a flash hider (they are about equal to the standard A2 flashhider), but they are awesome at minimizing recoil and muzzle climb : )